1. Field of the Invention
The invention relates to a metallic sliding slot structure, and more particularly to a metallic sliding slot structure for an electrical connector.
2. Description of the Related Art
A card-in/out device capable of hiding and positioning an inserted card and exposing an ejected card has been widely used in electrical products and computer peripheral products. The card may be, for example, a multimedia storage card or a memory card. The available memory cards for computers have several specifications and include a secure digital card (SDC), a multimedia card (MMC), a smart media card (SMC), a memory stick card (MSC), an XD-picture card (XDC), and the like.
The connector, which is to be connected to the inserted memory card and capable of hiding and positioning the inserted memory card and exposing the ejected memory card, is provided with a card-in/out device, as shown in FIGS. 1 and 2. The connector includes a base 10, terminals 25, a pushing piece 20, a guiding rod 26 and a spring 28.
The base 10 includes a bottom seat 11 and an upper cover 19 covering over the bottom seat 11. As shown in FIG. 3, the bottom seat 11 is made of plastic injection molding and is formed with a receiving slot 18 for receiving one memory card with a variable specification. One side of the receiving slot 18 is one-piece molded to form a heart-like sliding slot 12. One end of the slot 12 is formed with a starting point 13, and the other end of the slot is formed with a stroke point 14, a middle concave positioning point 15 and a card-out starting point 16. The sliding slot 12 is formed with several sloped blocks 7, as illustrated by hatched portions. Thus, a one-way circulation path from the starting point 13 to the stroke point 14, the positioning point 15, the card-out starting point 16 and the starting point 13 is created.
The terminals 25 are arranged in several rows and disposed on the bottom seat 11.
The pushing piece 20 having an inverse U-shape includes two sides pushing against two sides of the receiving slot 18 on the bottom seat 11. A connection hole 21 is formed at a front end of one side of the pushing piece 20.
Two ends of the guiding rod 26 are formed with longitudinal hooks 27 for hooking the connection hole 21 of the pushing piece 20 and the sliding slot 12 of the bottom seat 11, respectively.
The spring 28, which is disposed between the pushing piece 20 and a rear end of the bottom seat 11, provides an elastic force for moving the pushing piece 20, which moves toward the inside of the base 10, back to the original position.
According to the above-mentioned structure, the pushing piece 20 pushed by the inserted memory card drives the guiding rod 26 to slide in the sliding slot 12. Because the sliding slot 12 has a one-way circulation path, the guiding rod 26 is pushed from the starting point 13 to the stroke point 14 and then pulled back to the positioning point 15 and positioned at the positioning point 15 by the elastic force of the spring when the memory card is inserted. When the card is ejected, the memory card is also pushed, and the guiding rod 26 is pushed from the positioning point 15 to the card-out starting point 16 and then pulled back to the starting point 13 by the elastic force of the spring. Thus, the card in/out function can be achieved.
The conventional structure has the following drawbacks. Because the sliding slot 12 and the bottom seat 11 are formed by way of plastic injection molding, the shape of the sliding slot 12 and the sloped blocks 7 tend to be worn out to cause the sliding phenomena after several times of usage. Thus, the positioning points are unclear, or the positioning points cannot provide the function of effectively positioning, or the one-way circulation function disappears, thereby the electrical connector cannot work. In addition, the plastic material has poor intensity and the thickness has to be increased to enhance the intensity. So, the area of the sliding slot is enlarged, and the demand on the miniaturized electrical product cannot be met.
In addition, in order to enhance the long-lived property, some manufacturers adopt the metal casting method to integrally form the metallic sliding slot structure. However, this method has the following drawbacks. First, the manufacturing cost of metal casting is high. Second, the metal casting method cannot easily control the precise dimension and tends to form burrs and unsmooth surfaces, and is not suitable for the manufacturing of the precise elements.